Power management for modulated backlights

• US 10,460,679 B2
• Filed: 03/15/2017
• Issued: 10/29/2019
• Est. Priority Date: 09/30/2008
• Status: Active Grant

• Current Assignee: Dolby Laboratories Licensing Corporation (Dolby Laboratories Incorporated)
• Original Assignee: Dolby Laboratories Licensing Corporation (Dolby Laboratories Incorporated)
• Inventors: Wallener, Damir, Messmer, Neil W.
• Primary Examiner(s): Castiaux, Brent D
• Application Number:
  US15/459,114
• Publication Number:
  US 20170186380A1
• Time in Patent Office: 958 Days
• CPC Class Codes: G09G 2320/0626 for control of overall brightness
• CPC Class Codes: G09G 2320/0646 Modulation of illumination source brightness and image signal correlated to each other
• CPC Class Codes: G09G 2320/0686 with two or more screen areas displaying information with different brightness or colours
• CPC Class Codes: G09G 2330/021 Power management, e.g. power saving
• CPC Class Codes: G09G 2360/16 Calculation or use of calculated indices related to luminance levels in display data
• CPC Class Codes: G09G 3/342 using several illumination sources separately controlled corresponding to different display panel areas, e.g. along one dimension such as lines
• CPC Class Codes: G09G 3/36 using liquid crystals

Abstract

Power levels of a backlight are adjusted in a number of ways and based on a number of criteria. The adjustments result in a lower power consumption and, in some cases, may enhance audience attention to important objects in a scene. The adjustments comprise, for example, a combination of ramping down power (lowering final display brightness) in concert with corresponding compensatory LCD adjustments (increasing final display brightness). The adjustments may also include, for example, system dimming after ramp down/LCD adjustments are exhausted, or the shifting of an LDR2HDR curve.

Claims

1. A display, comprising:

a premodulator device including a plurality of individually controllable light sources and being configured to produce a first modulated light according to an image to be displayed, each of the individually controllable light sources being associated with at least one of a plurality of regions of the image to be displayed;

a primary modulator device illuminated by the first modulated light and configured to further modulate the first modulated light to produce further modulated light carrying the image to be displayed; and

a controller coupled to the premodulator device and the primary modulator device, the controller being configured

to evaluate image data representative of the image to be displayed to determine power information associated with each of the regions,

to compare the power information to a threshold power value, and

when the power information indicates an exceedance of the threshold power value, to reallocate power within the premodulator to implement a change in brightness of an area of the first modulated light associated with a particular region and to change modulation by the primary modulator device to accommodate the reallocation of power by the premodulator; and

wherein

the controller reallocates power by selectively decreasing the brightness of at least one area of the first modulated light and selectively increasing the brightness of another area of the first modulated light; and

an aggregate brightness of the first modulated light is decreased.

2. The display according to claim 1, wherein the controller is configured to evaluate the power information associated with each of the regions to determine total power utilized by the premodulator device.

3. The display according to claim 1, wherein the controller is configured to evaluate the power information associated with a particular one of the regions to determine power utilized in the particular region.

4. The display according to claim 1, wherein the controller is configured to evaluate the power information associated with a particular one of the regions to determine a rate of change of power utilized in the particular region.

5. The display according to claim 1, wherein the controller is additionally operative to determine whether the reallocation of power will result in a negative visual effect on the image to be displayed.

6. The display according to claim 5, wherein, when the controller determines that the reallocation of power will not result in a negative visual effect on the image to be displayed, then at least one region of the image to be displayed is adjusted relatively more or less than the other regions of the image to be displayed.

7. The display according to claim 6, wherein, when the controller determines that the reallocation of power will result in a negative visual effect on the image to be displayed, then the controller globally dims all of the regions of the image to be displayed.

8. The display according to claim 7, wherein the globally dimming of all regions of the image to be displayed includes reallocating power to a level a predetermined amount below the threshold power value.

9. In a display including a premodulator device and a primary modulator device, a method including:

evaluating image data representative of an image to be displayed to determine power information associated with portions of the premodulator device associated with at least one of a plurality of regions of the image to be displayed;

comparing the power information to a threshold power value to determine whether the power information indicates an exceedance of the threshold power value; and

when the power information indicates an exceedance of the threshold power value, reallocating power within the premodulator device to implement a change in brightness of an area of the primary modulator device illuminated by the premodulator device and to change modulation by the primary modulator device to accommodate the reallocation of power by the premodulator device; and

wherein

the step of reallocating power within the premodulator device includes reallocating power to selectively decrease the brightness of at least one area of the primary modulator device illuminated by the premodulator device and to selectively increase the brightness of another area of the primary modulator device illuminated by the premodulator device; and

an aggregate brightness of areas of the primary modulator device is decreased.

10. The method according to claim 9, further comprising evaluating the power information associated with each of the regions to determine total power utilized by the premodulator device.

11. The method according to claim 9, further comprising evaluating the power information associated with a particular one of the regions to determine power utilized by a portion of the premodulator device associated with the particular region.

12. The method according to claim 9, further comprising evaluating the power information associated with a particular one of the regions to determine a rate of change of power utilized by a portion of the premodulator device associated with the particular region.

13. The method according to claim 9, further comprising determining whether the reallocation of power will result in a negative visual effect on the image to be displayed.

14. The method according to claim 13, further comprising adjusting at least one region of the image to be displayed relatively more or less than the other regions of the image to be displayed when it is determined that the reallocation of power will not result in a negative visual effect on the image to be displayed.

15. The method according to claim 14, further comprising globally dimming all of the regions of the image to be displayed when it is determined that the reallocation of power will result in a negative visual effect on the image to be displayed.

16. The method according to claim 15, further comprising globally dimming of all regions of the image to be displayed by reallocating power to a level a predetermined amount below the threshold power value.

17. A non-transitory electronically-readable medium having code embodied therein that when executed causes an electronic device to:

evaluate image data representative of an image to be displayed to determine power information associated with portions of a premodulator associated with at least one of a plurality of regions of the image to be displayed;

compare the power information to a threshold power value to determine whether the power information indicates an exceedance of the threshold power value; and

when the power information indicates an exceedance of the threshold power value, reallocate power within the premodulator to implement a change in brightness of an area of a primary modulator illuminated by the premodulator associated with a particular region and to change modulation by the primary modulator to accommodate the reallocation of power by the premodulator; and

wherein

the step of reallocating power within the premodulator includes reallocating power to selectively decrease the brightness of at least one area of the primary modulator illuminated by the premodulator and to selectively increase the brightness of another area of the primary modulator illuminated by the premodulator; and

an aggregate brightness of areas of the primary modulator is decreased.

18. The non-transitory electronically-readable medium according to claim 17, wherein said code when executed further causes said electronic device to evaluate the power information associated with each of the regions to determine total power utilized by the premodulator.

19. The non-transitory electronically-readable medium according to claim 17, wherein said code when executed further causes said electronic device to evaluate the power information associated with a particular one of the regions to determine power utilized by a portion of the premodulator associated with the particular region.

20. The non-transitory electronically-readable medium according to claim 17, wherein said code when executed further causes said electronic device to evaluate the power information associated with a particular one of the regions to determine a rate of change of power utilized by a portion of the premodulator associated with the particular region.